I really like Meiling. I think her flaws made her more realistic, she showed her love more physically, which is entirely true when comparing to real life scenarios. Its also nice to see Sakura and Mei Ling both fell in love with Syaoran-kun's kindness.
I dont think the anime would be nearly as memorable without Meiling. Not only did she spice things up, she was the person who made things more humorous, dramatic and even sadder. Meiling also triggered that special kindness Syaoran doesn't show people. Its nice to see the kind of impact she has on people.
Frankly, the anime wouldn't be as awesome without Meiling-chan